Pullet shaken by dog, 1 day later staggers around and sits still mostly

Our chick got out of a temporary run and was caught and shaken by a dog. We got the bird away after a few second. The dog pulled a few feathers out and shook the bird, but a close inspection revealed no obvious wounds or broken wings/legs.

The first few hours the chick tried to feed and drink water normally, but mostly staggered around. Now about 24 hours later, she is sitting in a corner of a cardboard box with warmer 99% of the time.